Attachment mechanism for surgical tool tracking system

ABSTRACT

An attachment mechanism for a rotating surgical tool includes a mounting body defining a tool passage therein and configured for connection to a non-rotational component of the surgical tool, such that the tool passage is concentric about a rotational component of the surgical tool. The attachment mechanism further includes a ring arranged around the tool passage and rotatably connected to the mounting body. A mounting arm is attached to the ring such that rotation of the ring relative to the mounting body sets a desired circumferential position of the mounting arm relative to the tool passage, the mounting arm being configured to receive a tracking system emitter. An engagement mechanism is operable between the ring and the mounting body to maintain the desired circumferential position of the mounting arm.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No.15/353,970, filed on Nov. 17, 2016, which claims the benefit of U.S.Provisional Patent Application Ser. No. 62/256,789, filed on Nov. 18,2015, the contents of which applications are herein incorporated byreference in their entirety.

FIELD OF THE INVENTION

The present invention relates to systems and methods for trackingsurgical tools, and more particularly, to an attachment mechanism forfacilitating attachment of a tracking device to a rotating surgicaltool.

BACKGROUND OF THE INVENTION

Accurate tracking of the motion into a patient's body of a surgicaltool, for instance, a drill bit, is crucial for ensuring appropriateutilization of the tool during surgery. Current surgical tool trackingsystems typically make use of pre-operative techniques, such as MRI orCT scans, in combination with intra-operative techniques, for instance,X-ray imaging. Such techniques, however, are quite cumbersome. Forexample, the techniques increase radiation exposure to surgeon andpatient, and ultimately, only provide two-dimensional spatialinformation. Some current surgical tool tracking systems also use videocameras or other localizing devices to track the movement of surgicaltools in three-dimensional space. However, further improvements arepossible to develop a tracking system that can be incorporated with anysurgical tool and accurately track its motion.

SUMMARY OF THE INVENTION

In view of the foregoing, it is an object of the present invention toprovide an attachment mechanism for a rotating surgical tool. Theattachment mechanism includes a mounting body defining a tool passagetherein and configured for connection to a non-rotational component ofthe surgical tool, such that the tool passage is concentric about arotational component of the surgical tool. The attachment mechanismfurther includes a ring arranged around the tool passage and rotatablyconnected to the mounting body. A mounting arm is attached to the ringsuch that rotation of the ring relative to the mounting body sets adesired circumferential position of the mounting arm relative to thetool passage, the mounting arm being configured to receive a trackingsystem emitter. An engagement mechanism is operable between the ring andthe mounting body to maintain the desired circumferential position ofthe mounting arm.

According to another embodiment of the present invention, a method fortracking a spatial location of a surgical tool includes connecting atracking system emitter to a mounting arm of an attachment mechanismconnected to a non-rotational component of the surgical tool, such thattool passage of a mounting body of the attachment mechanism isconcentric with a rotational component of the surgical tool. Themounting arm of an attachment mechanism is rotated via a ring extendingaround the tool passage to set a desired circumferential position of thetracking system emitter. The spatial location of the tracking systememitter is tracked using a localizer in the vicinity thereof.

These and other objects, aspects and advantages of the present inventionwill be better understood in view of the drawing and following detaileddescription of preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an attachment mechanism connected abouta rotational component of a surgical tool, according to an embodiment ofthe presented invention;

FIG. 2 is an end view of a ring of the attachment mechanism of FIG. 1;

FIG. 3 is a partial sectional view the attachment mechanism of FIG. 1,with hidden components shown in broken lines;

FIG. 4 is an overview of a surgical tool tracking system, including theattachment mechanism of FIG. 1 in use on a surgical drill; and

FIG. 5 is a flow chart illustrating a method of using the attachmentmechanism, according to one embodiment of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to FIGS. 1-3, according to an embodiment of the presentinvention, an attachment mechanism 10 for a surgical tool includes atool mounting body 12, a ring 14, and a tracking device mounting arm 16.The tool mounting body 12 is configured for connection to anon-rotational component 18 of the surgical tool 20, such as a toolhousing, concentric about a rotational component 20, such as a chuck,bit or shaft. The mounting body 12 connects to the non-rotationalcomponent 18 so as to avoid rotation with the rotational component 20,while the ring 14 and mounting arm 16 can be selectively rotatedrelative to the mounting body 12, allowing a desired circumferentialposition of the mounting arm 16 to be set. An engagement assembly 22 isadvantageously provided to maintain the desired circumferentialposition, once set.

In the depicted embodiment, the mounting body 12 defines a tool passage24 through which the rotational component 20 passes, the tool passage 24preferably being coaxial with the rotation component 20. The mountingbody 12 further includes first and second plates 26, 28, arranged onopposite axial ends of the ring 14 and through which the tool passage 24extends. At least one of the plates 26, 28 is affixed (e.g., welded) tothe non-rotational component 18, and therefore does not rotate with therotational component 20 (e.g., a shaft) while the tool is in use. Themounting body 12 is preferably generally cylindrical and made of steelor another suitable material.

The ring 14 is mounted coaxially about the rotating component 20 andthus rotates relative to the mounting body 12. In the depictedembodiment, the ring 14 is mounted between the first and second plates26 and 28. The rotational position of the ring 14 is maintained byfrictional or other engagement generated by the engagement assembly 22relative to the mounting body 12. The ring 14 is preferably made ofsteel or another suitable material.

The engagement assembly 22 is configured to maintain the ring 14 in adesired circumferential position. For example, the engagement assembly22 can include a plurality of locking members 30, such as spring screws,ball spring plungers, and/or other biased engagement mechanisms,installed on facing surfaces of the mounting body 12 and the ring 14 toand generating mutual engagement therebetween. In the depictedembodiment, the four circumferentially spaced locking members 30 areinstalled in the ring 14 and extend toward the mounting body 12.Circumferentially spaced detents 32 can be formed on a facing surface ofthe second plate 28, which provides positions enhanced engagement. Othertypes of torqueing and/or tensioning mechanisms can also be used toprevent rotation of the ring 14 once a desired circumferential positionis found.

The mounting arm 16 extends radially outward from the ring 14 andpreferably includes a mounting adapter 34 at a distal end thereofconfigured to receive a tracking system emitter. The mounting arm 16rotates around the mounting body 12 as the ring 14 rotates. As such, thecircumferential position of the mounting arm 16 relative to the mountingbody 12 can be adjusted by rotating the ring 14 and maintained via theengagement assembly 22. The mounting arm 16 preferably has an elongatedshape and is made of steel or another rigid material.

The various parts of the attachment mechanism 10 can be varied in sizeto suit the shape and size of the surgical tool to which it is attached.The attachment mechanism 10 can be made of steel, other appropriatemetal alloys, plastic or a combination thereof.

FIG. 4 illustrates the attachment mechanism 10 attached to a surgicaldrill 40 in a spine surgery environment. Specifically, one or moreemitters 42 are mounted on the mounting arm 16 to facilitatedetermination of the position of the rotational component 20 relative toa patient's body. As an example, the one or more emitters 42 can bevisible-spectrum emitters, such as common light-emitting diodes (LEDs),or other suitable electromagnetic radiation emitters suitable foraccurate locating by an appropriate localizer 44, for example, a camera.A surgeon holds the surgical drill 20 and adjust and lock the positionof the mounting arm 16 as needed for a particular medical procedure. Thelocalizer 44 monitors the position and movement of the emitters 42relative to the patient's anatomical structures. A computer system canbe used for automatic transformation of the data collected by thelocalizer 44 into three-dimensional coordinates of the emitters 42.Given information on the locations of the emitters 42 relative to thesize and shape of the drill, the three-dimensional coordinates of theemitters 42 can be used for automatic transformation into thethree-dimensional coordinates of the rotational component 20, providinginformation on the location of the rotational component 20 relative tothe patient's anatomical structures. The motion of the rotationalcomponent 20 relative to the patient's body can also be displayed on amonitor 46 for viewing by medical personnel.

Referring to FIG. 5, a method for tracking a spatial location of asurgical tool includes, at step 502, connecting a tracking systememitter (e.g., emitter 42) to a mounting arm (e.g., mounting arm 16) ofan attachment mechanism connected to a non-rotational component (e.g.,non-rotational component 18) of the surgical tool (e.g., surgical drill40), such that tool passage of a mounting body (e.g., mounting body 12)of the attachment mechanism is concentric with a rotational component ofthe surgical tool. At step 504, the mounting arm (e.g., mounting arm 16)of an attachment mechanism is rotated via a ring (e.g., ring 14)extending around the tool passage to set a desired circumferentialposition of the tracking system emitter (e.g., emitter 42). At step 506,the spatial location of the tracking system emitter is tracked using alocalizer (e.g., localizer 44) in the vicinity thereof.

In general, the foregoing description is provided for exemplary andillustrative purposes; the present invention is not necessarily limitedthereto. Rather, those skilled in the art will appreciate thatadditional modifications, as well as adaptations for particularcircumstances, will fall within the scope of the invention as hereinshown and described.

What is claimed is:
 1. An attachment mechanism for a rotating surgicaltool comprising: a mounting body defining a tool passage therein andconfigured for connection to a non-rotational component of the surgicaltool, such that the tool passage is concentric about a rotationalcomponent of the surgical tool; a ring arranged around the tool passageand rotatably connected to the mounting body; a mounting arm attached tothe ring such that rotation of the ring relative to the mounting bodysets a desired circumferential position of the mounting arm relative tothe tool passage, the mounting arm being configured to receive atracking system emitter; and an engagement mechanism operable betweenthe ring and the mounting body to maintain the desired circumferentialposition of the mounting arm.
 2. The attachment mechanism of claim 1,wherein the mounting body includes a first plate arranged on a first endof the ring, the tool passage extending through the first plate.
 3. Theattachment mechanism of claim 2, wherein the mounting body furtherincludes a second plate arranged on a second end of the ring oppositethe first plate, the tool passage also extending through the secondplate.
 4. The attachment mechanism of claim 1, wherein, when themounting body is connected to the non-rotational component of thesurgical tool, the ring is coaxial with the rotational component.
 5. Theattachment mechanism of claim 1, wherein the engagement mechanismincludes at least one locking member extending between the mounting bodyand the ring and biased to generate frictional engagement therebetween.6. The attachment mechanism of claim 5, further comprising a pluralityof circumferentially spaced detents formed on at least one of themounting body and the ring and positioned for engagement by the at leastone locking member, such that an engagement force between the mountingbody and the ring is enhanced.
 7. The attachment mechanism of claim 6,wherein the at least one locking member extends from the ring and theplurality of circumferentially spaced detents are formed on the mountingbody.
 8. The attachment mechanism of claim 7, wherein the mounting bodyincludes a first plate arranged on a first end of the ring, the toolpassage extending through the first plate, the plurality ofcircumferentially spaced detents being formed on the first plate facingthe ring.
 9. The attachment mechanism of claim 5, wherein the mountingbody includes a first plate arranged on a first end of the ring, thetool passage extending through the first plate, the at least one lockingdevice extending between the first plate and the ring.
 10. Theattachment mechanism of claim 1, further comprising the tracking systememitter attached to the mounting arm.
 11. A surgical tool assemblycomprising: a surgical tool having a non-rotational component and arotational component; a mounting body defining a tool passage thereinand configured for connection to the non-rotational component of thesurgical tool, such that the tool passage is concentric about therotational component of the surgical tool; a ring arranged around thetool passage and rotatably connected to the mounting body; a mountingarm attached to the ring such that rotation of the ring relative to themounting body sets a desired circumferential position of the mountingarm relative to the tool passage, the mounting arm being configured toreceive a tracking system emitter; and an engagement mechanism operablebetween the ring and the mounting body to maintain the desiredcircumferential position of the mounting arm.
 12. The attachmentmechanism of claim 11, wherein the non-rotational component is a toolhousing.
 13. The attachment mechanism of claim 11, wherein the surgicaltool is a surgical drill and the rotational component includes at leastone of a drill bit, a chuck and a shaft.